Graft fixation device

ABSTRACT

A graft fixation device combination. The device is useful for affixing a tissue graft to a bone or other body surface. The fixation device has two implantation members connected by a graft retention member. The retention member optionally has at least one lateral wing member extending therefrom. The implantation members have longitudinal passageways therethrough. The graft fixation device also has an insertion member extending from the distal end of each implantation member, the insertion member having a longitudinal passage having a distal blind wall. The passages of the implantation members and the insertion members are in communication with each other, and may be mounted onto insertion members.

This is a Continuation-In-Part application of commonly assignedco-pending U.S. patent application Ser. No. 09/793,036 filed on Feb. 26,2001 now U.S. Pat. No. 6,402,766 which is a Continuation-In-Partapplication of commonly-assigned, copending U.S. patent application Ser.No. 09/535,183 filed on Mar. 27, 2000 which is a Continuation-In-Part ofcommonly-assigned, copending patent application U.S. patent applicationSer. No. 09/360,367 filed on Jul. 23, 1999 now U.S. Pat. No. 6,179,840,which are incorporated by reference.

TECHNICAL FIELD

The field of art to which this invention relates is surgical fasteningdevices, in particular, surgical fastening devices for fixating tissuegrafts to bone.

BACKGROUND OF THE INVENTION

The medical technology associated with tissue engineering has advancedat a rapid pace. In particular, it is now known to harvest cells fromthe human body, for example, chondrocytes and fibrochrondrocytes fromthe knee joint. These autologous cells are then cultured in a laboratoryenvironment on a bioabsorbable matrix. The matrix will typically have ashape substantially similar to the tissue section which needs to bereplaced. After a sufficient period of time in an appropriate culturemedium at the proper environmental conditions, the harvested cells willgrow on the matrix to form an implantable section of tissue havingsubstantially the same physical configuration as the section of tissuewhich needs to be replaced in the patient. Such a tissue-engineeredconstruct, consisting of cells on the matrix (or, alternatively,consisting of a matrix alone without cells), is then affixed to the bonesite using conventionally known surgical fasteners including sutures,periosteal coverings, or fibrin glue.

The advantages of tissue engineering are many, not the least of whichis, for example, that it is now possible to replace cartilage withliving cartilage tissue. In addition, the likelihood of rejection of thetissue implant is minimized since the cartilage tissue which has beengrown in-vitro is identical to the autologous cartilage of the patient.

Although existing matrix fixation devices are adequate for theirintended use, there are also some disadvantages attendant with theiruse. First of all these fixation devices are generic in the sense thatthey are not specifically designed for matrix fixation to bone or softtissue, but can be used for a variety of surgical procedures. Otherdisadvantages include the difficulty in using many of these devices in aminimally invasive arthroscopic procedure. Additional disadvantagesinclude the difficulty and surgical challenge of harvesting a piece ofperiosteum for use as a periosteal flap, the significant patientmorbidity associated with such harvesting, and the difficulty insuturing such a thin, compliant material to surrounding tissue.

Accordingly, there is a need in this art for novel fixation devices thatwill effectively affix a matrix of tissue-engineered tissue to a bone orother anchoring site so that the tissue may continue to grow andregenerate in the patient's body.

DISCLOSURE OF THE INVENTION

Therefore, it is an object of the present invention to provide afixation device that effectively fixates a tissue-engineered matrix to abone or other anchoring site, thereby enabling the implanted matrix toremain in place while the tissue continues to grow and regenerate.

It is a further object of the present invention to provide such a devicefor fixating a matrix to a bone site which is easily installed using anarthroscopic procedure or an open procedure.

It is yet a further object of the present invention to provide such adevice for fixating a matrix to a bone site which does not requiresutures or suture knot tying.

It is still yet a further object of the present invention to provide asurgical method for fixating a matrix utilizing such a device in alocation within a patient's body.

Accordingly, a graft fixation device is disclosed. The graft fixationdevice has first and second implantation members. The members areelongated and preferably have a cylindrical configuration. The membersalso have distal ends, proximal ends, and longitudinal axes. There arelongitudinal passages extending through the entire length of eachimplantation member. The members have outer surfaces. The implantationmembers are connected to each other by a rod member having first andsecond ends and a central section. The first end of the rod memberextends from the proximal end of the first implantation member and thesecond end of the rod member extends from the proximal end of the secondimplantation member. The rod member is preferably relatively rigid andmay be configured to have a variety of geometric shapes, for example, aninverted “U” shape. However, the rod member may also be flexible. Therod member maintains the implantation members at a relatively fixeddistance from each other. The central section of the rod member isdesigned to engage a section of a tissue-engineered matrix implant. In apreferred embodiment, the implantation members have a series of ridgesextending out from the outer surfaces of the implantation members toassist in preventing withdrawal from a bone site or other anchoring siteafter the implantation members are implanted into previously-createdbore holes.

Yet another aspect of the present invention is a method of using thegraft fixation device of the present invention to affix a matrixcontaining tissue-engineered tissue to a bone.

Still yet another aspect of the present invention is a graft fixationdevice combination which is the combination of a fixation device and aninsertion device. The fixation device has a first implantation member.The implantation member has a longitudinal axis, a proximal end, adistal end, an outer surface, and a longitudinal passage therethrough.The fixation device also has a second implantation member. The secondimplantation member has a longitudinal axis, a proximal end, a distalend, an outer surface, and a longitudinal passage therethrough. Eachimplantation member has a proximal annular face on its proximal endsurrounding the longitudinal passages. There is a connecting memberconnecting the first and second implantation members. The connectingmember has a central section, a first end extending from the firstimplantation member and a second end extending from the secondimplantation member. There are a pair of insertion devices. Eachinsertion device is a member having a proximal end, a distal tapered endand a longitudinal passage therethrough. The distal end of eachimplantation member is in engagement with the proximal end of aninsertion device. Optionally an insertion device is mounted to thedistal end of an implantation member.

Yet another aspect of the present invention is a graft fixation device.The graft fixation device has first and second implantation members. Themembers are elongated and preferably have a cylindrical configuration.The members also have distal ends, proximal ends, and longitudinal axes.There are longitudinal passages extending through the entire length ofeach implantation member. The members have outer surfaces. Theimplantation members are connected to each other by a rod member havingfirst and second ends and a central section. The first end of the rodmember extends from the proximal end of the first implantation memberand the second end of the rod member extends from the proximal end ofthe second implantation member. The rod member is preferably relativelyrigid and may be configured to have a variety of geometric shapes, forexample, an inverted “U” shape. However, the rod member may also beflexible. The rod member maintains the b The wing member facilitatessuch engagement. In a preferred embodiment, the implantation membershave a series of ridges extending out from the outer surfaces of theimplantation members to assist in preventing withdrawal from a bone siteor other anchoring site after the implantation members are implantedinto previously-created bore holes.

Yet another aspect of the present invention is a method of using theabove-described graft fixation device having a laterally extending wingmember to affix a matrix containing tissue-engineered tissue to a bone.

A further aspect of the present invention is a graft fixation devicecombination which is the combination of a fixation device and aninsertion device. The fixation device has a first implantation member.The implantation member has a longitudinal axis, a proximal end, adistal end, an outer surface, and a longitudinal passage therethrough.The fixation device also has a second implantation member. The secondimplantation member has a longitudinal axis, a proximal end, a distalend, an outer surface, and a longitudinal passage therethrough. Eachimplantation member has a proximal annular face on its proximal endsurrounding the longitudinal passages. There is a connecting rod memberconnecting the first and second implantation members. The connecting rodmember has a central section, a first end extending from the firstimplantation member and a second end extending from the secondimplantation member. Extending laterally outward from the connectingmember is at least one wing member. There are a pair of insertiondevices. Each insertion device is a member having a proximal end, adistal tapered end and a longitudinal passage therethrough. The distalend of each implantation member is in engagement with the proximal endof an insertion device. Optionally an insertion device is mounted to thedistal end of an implantation member.

Yet another aspect of the present invention is a method of using theabove-described graft fixation device combination having a laterallyextending wing member to affix a matrix containing tissue-engineeredtissue to a bone.

A further aspect of the present invention is a graft fixation device.The graft fixation device has a first implantation member and a secondimplantation member. Each implantation member has an outer surface, alongitudinal axis, a proximal end and a distal end. Extending from, ormounted to, the distal end of each implantation member is a penetratinginsertion member. The implantation members have a longitudinal passage,and proximal and distal openings in communication with the passage. Theinsertion members have outer surfaces, proximal ends, distal ends, andlongitudinal axes. Each insertion member has a longitudinal passage anda proximal opening. The longitudinal passage has a distal closed, blindend. The proximal opening of each insertion member is in communicationwith the distal opening of the implantation member and the longitudinalpassage of the insertion member. The implantation members are connectedto each other by a retention member having first and second ends and acentral section. The first end of the retention member extends from theproximal end of the first implantation member and the second end of theretention member extends from the proximal end of the secondimplantation member. The retention member is preferably relativelyrigid, and may be configured to have a variety of geometric shapes, forexample, an inverted “U” shape. However, the retention member may alsobe flexible. Optionally, extending laterally outward from the retentionmember is at least one wing member. The central section of the retentionmember with the optional wing member may engage a section of an implantsuch as a tissue-engineered matrix implant.

Yet another aspect of the present invention is a method of using theabove-described graft fixation device to affix a matrix to a bone, e.g.,to mount a matrix to a bone.

Still yet a further aspect of the present invention is a novelinstrument which can be used in a surgical procedure to insert theabove-described graft fixation device in bone.

These and other features and advantages of the present invention willbecome more apparent from the following description and accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a graft fixation device of the presentinvention.

FIG. 2 is a cross-sectional view of the graft fixation device of FIG. 1taken along view line 2—2.

FIGS. 3-6 illustrate a surgical procedure for affixing a matrix to boneusing the graft fixation device of the present invention.

FIG. 7 is an illustration of a graft fixation device of the presentinvention after the implantation members have been implanted in boreholes in bone illustrating the device affixing a matrix securely to thesurface of a bone.

FIG. 8 is a cross-sectional view of the graft fixation device of FIG. 7implanted in bone, and taken along View Line 8—8.

FIG. 9 is an alternative embodiment of a graft fixation device of thepresent invention having two connecting members.

FIG. 10 is a perspective view of an instrument useful for making boreholes in bone into which the implantable members of the graft fixationdevices of the present invention may be emplaced.

FIG. 11 is a perspective view of an instrument useful for implanting thedevice of the present invention into bore holes made in bone.

FIG. 12 is a view of a tissue engineered matrix secured to a bone withseveral graft fixation devices of the present invention.

FIG. 13 is a perspective view of an alternate embodiment of a graftfixation device of the present invention.

FIG. 14 is a side view of the graft fixation device of FIG. 13.

FIG. 15 is an end view of the graft fixation device of FIG. 14.

FIG. 16 is a cross-sectional view of the graft fixation device of FIG.14, taken along View-Line 16—16.

FIG. 17 is a cross-sectional view of the tissue retention member of thegraft fixation device of FIG. 14, taken along View-Line 17—17.

FIG. 18 is a perspective view of an insertion member useful to insert agraft fixation member of the present invention.

FIG. 19 is an exploded perspective view of an insertion instrument, agraft fixation device, and two insertion members.

FIG. 20 is a side view of the distal end of the insertion instrument, agraft fixation device, and insertion members engaged in bone, prior toremoval of the insertion device.

FIG. 21 is a cross-sectional view taken along View-Line 21—21 of FIG. 20of the prong of the insertion instrument, and a section of the retentionmember engaged in a longitudinal groove of the prong.

FIG. 22 is an exploded perspective view of the distal end of aninsertion instrument of the present invention, illustrating a removabledistal end assembly for creating bore holes in bone for receiving thefixation devices of the present invention, wherein the assembly has anend member and pins.

FIG. 23 is a cross-section of the assembly end member of FIG. 22, takenalong View-Line 23.

FIG. 24 is a perspective view of the assembly end of FIG. 22, completelyassembled and ready for use.

FIG. 25 is a cross-sectional view of the end assembly of FIG. 24, takenalong View-Line 25—25.

FIG. 26 is an exploded perspective view of an insertion instrument ofthe present invention having a removable distal end assembly useful forinserting the graft retention members of the present invention into boreholes in a bone, having an end assembly member and two pins; when usedwith insertion members, the instrument can be used to emplace thefixation devices directly into bone without first forming bone boreholes.

FIG. 27 is a cross-sectional view of the end assembly member of FIG. 26.

FIG. 28 is a perspective view of the distal end of the insertioninstrument of FIG. 26, having the end assembly member and prongs fullyassembled and mounted.

FIG. 29 is a cross-sectional view of the distal end of the insertioninstrument of FIG. 28 take along View-Line 29—29.

FIG. 30 is a cross-sectional view of the instrument of FIG. 29 takenalong View-Line 30—30.

FIG. 31 illustrates a fixation device of the present member having aninsertion member molded into the distal end of each implantation member.

FIG. 32 is a cross-sectional view of the fixation device of FIG. 31.

FIG. 33 is a perspective view of an alternate embodiment of a graftfixation device of the present invention having laterally extending wingmembers.

FIG. 34 is a view of a matrix secured to a bone with several graftfixation members of FIG. 33.

FIG. 35 is a perspective view of yet another alternate embodiment of agraft fixation device of the present invention having laterallyextending wing members.

FIG. 36 is a view of a matrix secured to a bone with several graftfixation members of FIG. 35.

FIG. 37 is a perspective view of an alternate embodiment of a graftfixation device of the present invention; the implantation member has alongitudinal passage that extends partially therethrough.

FIG. 38 is a cross-sectional view of the graft fixation device of FIG.37 taken along View-Line 38—38, also illustrating the mounting prongs ofthe insertion instrument.

FIG. 39 is a top view of a matrix secured to a bone with several of thegraft fixation members of FIG. 37.

FIG. 40 is a cross-sectional view of the retention member of thefastener of FIG. 37 taken along View-Line 40—40.

FIG. 41 is a cross-sectional view of the retention member of thefastener of FIG. 37 taken along View-Line 41—41.

FIG. 42 is an exploded perspective view of an insertion instrumentuseful to apply the fasteners of FIG. 37.

FIG. 42A is a partial magnified perspective view of the distal end ofthe shaft of the instrument of FIG. 42 illustrating the mounting prongs.

FIG. 43 is a perspective view of the instrument of FIG. 43 mounted to aslap hammer.

FIG. 44 is a cross-sectional view of the instrument of FIG. 43 takenalong View Line 44—44.

FIG. 45 is a cross-sectional view of the instrument of FIG. 44 takenalong View Line 45—45.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The graft fixation devices of the present invention can be made fromconventional bio-compatible materials, including absorbable andnon-absorbable materials, as well as biodegradable materials. Thenon-absorbable materials which can be utilized include conventionalbiocompatible materials such as stainless steel, polyethylene, Teflon,Nitinol, non-absorbable polymers, other bio-compatible metals, ceramics,combinations thereof and the like. The absorbable materials which can beused to manufacture the graft fixation devices of the present inventionwill typically include those conventional bioabsorbable or bioresorbablematerials known in this art which can be effectively molded or machined.The bio-absorbable and bio-resorbable materials include polylactic acid,polydioxanone, polycaprolactone, polyglycolic acid, polygalactic acid,other known biocompatible bioabsorbable and bioresorbable polymers,ceramics, composites, combinations thereof and the like and equivalentsthereof.

Referring now to FIGS. 1-2, a preferred embodiment of a graft fixationdevice 10 of the present invention is illustrated. The graft fixationdevice 10 is seen to have implantation members 20. The implantationmembers 20 are seen to be elongated members, preferably having asubstantially cylindrical shape. The members 20 may have other geometricshapes including conical, pyramidal, polygonal, cubic, spherical, etc.The implantation members 20 are seen to have distal ends 22 and proximalends 24. Each implantation member 20 is seen to have an outer surface 28and a longitudinal axis 29. Each member 20 is also seen to havelongitudinal passage 35 extending therethrough. The implantation members20 are also seen to have optional frustoconical ends 30, and proximalendface surfaces 32. Although it is preferred that endface surfaces 32be flat, endface surface 32 may also be angled, concave, convex, etc.Endface surface 32 is seen to have central circular opening 36 incommunication with passage 35. Preferably, central opening 36 will havea circular cross-section, but it may have other geometric cross-sectionsas well including elliptical, polygonal, square, rectangular,combinations thereof and the like. Members 20 are also seen to havedistal end face surfaces 37 having circular openings 38 in communicationwith passages 35. As shown with the optional frustoconical end 30, theannular end face surface 37 is of de minimis thickness around opening38, however this thickness would increase in the absence of afrustoconical end. Also seen to extend out from the surface 28 of member20 are a series of optional projections 40 having tissue engagementedges 44. Without the projections 40, the surface 28 of the member 20will be smooth.

The device 10 is seen to have graft retention member 50 connecting theimplantation members 20. Retention member 50 is seen to be a rod-likemember having first end 52, second end 54 and central section 55. Firstend 52 is seen to extend from proximal endface surface 32 of the firstmember 20 while end 54 is seen to extend up from the proximal endfacesurface 32 of the other member 20. The ends 54 and 52 of retentionmember 50 may also if desired extend from or be mounted to any sectionof outer surface 28. The connecting member 50 is seen to be preferablybent or shaped into three segments including top segment 55 and legsegments 56. The top segment 55 is seen to be substantiallyperpendicular to the leg segments 56. Although it is preferred thatconnecting member 50 have an inverted “U” configuration, the connectingmember 50 may have other geometric configurations includingsemicircular, arced, curved, triangular, polygonal, U-shaped, and thelike and combinations thereof. The ends 52 and 54 of connecting member50 may be permanently affixed to the implantation members 20, or may beremovably attached thereto in a conventional manner. Member 50 may berigid or flexible. Member 50 will have a sufficient surface area toeffectively retain a tissue-engineered matrix in place on a bone orother body surface. Preferably, connecting member 50 will have acircular cross-section, but may have other geometric cross-sections aswell including elliptical, polygonal, square, rectangular, combinationsthereof and the like. Member 50 may be rigid or flexible, and may have asingle filamentary structure or have multiple interconnected filamentsor members.

Referring now to FIGS. 3-8, the use of the graft fixation devices 10 ofthe present invention in a surgical procedure is illustrated. Referringfirst to FIG. 3, the initial step, prior to the installation of a matrixcontaining a tissue-engineered tissue using a graft fixation device 10of the present invention, is to drill or “tap” two bore holes 200 into abone 210, for example, subchondral bone in the knee joint. The boreholes 200 are seen to be cylindrical holes having a bottom 208 and anopen top 202 and side walls 205. Optionally, the bore holes may be bonetunnels with a continuous passage and no bottom, or an open bottom. Itis particularly preferred to tap the holes in the bone by using aninstrument 400 as illustrated in FIG. 10 which has a proximal sectionconventionally referred to in this art as a “slap hammer” section. Theterm “tapping” or “tap” as used herein is defined to mean a procedurewherein the distal pointed prongs 420 extending from the distal end 415of the shaft 405 of instrument 400 are located over a bone site, and theproximal end 410 of instrument 400 is tapped or hit with slidable hammerhandle 450 (of the “slap hammer”), which slides on shaft 460 betweenproximal end 410 and proximal stop 470, to form the bone bore holes 200.The distal end 465 of shaft 460 is connected to proximal end 411.Proximal stop 470 is mounted to proximal end 467. Hammer handle 450 isseen to have grasping section 451, collars 455 and longitudinal passage457. Those skilled in the art will appreciate that a similar pointedinstrument may be used to “tap” in the bore holes into bone, that is,any instrument having a nail-like distal end. In addition, although notpreferred, one bone bore hole at a time may be “tapped” in. If thesurgeon decides to drill the bore holes into bone, any conventionalsurgical drilling apparatus may be used. After the bore holes 200 areformed into the bone 210, the matrix 220 containing tissue-engineeringtissue is placed upon the bone surface 201 by the surgeon as seen inFIG. 4. Next, the graft fixation device 10 is mounted on to theinsertion instrument 250. Insertion instrument 250, as illustrated inFIG. 11, is seen to be an elongated rod 260 having a proximal end 262and a distal end 264. Mounted to the distal end 264 of the rod 260 isthe depth stop 290. The depth stop 290 is seen to be a substantiallyrectangular member which is mounted perpendicular to the longitudinalaxis 251 of the rod 260. Depth stop 290 is seen to have bottom 292.Extending distally from the bottom 292 of plate member 290 is a pair ofparallel, spaced-apart, mounting prongs 270. The mounting prongs 270 areseen to be substantially rod-like members having distal pointed tips 277and proximal ends 272. The prongs 270 are seen to have first section 273and distal section 275. Section 273 is seen to have a greatercross-sectional dimension than distal section 275 such that the entiresection 275 is insertable into passages 35 of members 20, while proximalsection 273 is not insertable therein. Instrument 250 is also seen tohave a “slap hammer section” consisting of proximal shaft 300 extendingfrom proximal end 262, slidable hammer handle 320 (the “slap hammer”)which is slidable upon shaft 300 between proximal end 262, and proximalstop 330. Hammer handle member 320 is seen to have grasping section 325,end collars 327 and longitudinal passage 329. The graft fixation device10 is mounted to the insertion instrument 250 by sliding theimplantation members 20 onto the prongs 270 such that the distalsections 275 of members 270 are engaged within the longitudinal passages35 of members 20 and distal points 277 protrude beyond the end of distalendface surfaces 37. Then, as seen in FIGS. 5 and 6, the instrument 250is manipulated such that the graft fixation device 10 is insertedthrough matrix 220 and into bone 210 by moving the implantation members20 mounted on prongs 270 into the bore holes 200 such that the members20 are engaged in the bore holes 200, and such that the tissueengagement section 55 of the retention member 50 engages the matrix 220such that the matrix 220 is firmly engaged against the surface 201 ofthe bone 210. If desired, holes may be cut into matrix 220 prior toinsertion of device 10. Then, as seen in FIG. 7, the insertioninstrument 250 is withdrawn proximally causing the prongs 270 to bewithdrawn from the passages 35 of the implantation members 20, therebyleaving the graft fixation device 10 engaged in the bone bore holes, andcausing the matrix 220 to be maintained in engagement with the surface201 of bone 210. The “slap hammer” section of instrument 250 may assistin removal of the prongs. A cross-sectional view illustrating the device10 engaged in bone 210 while maintaining the matrix 220 on bone surface201 is seen in FIG. 8.

FIG. 12 illustrates a matrix 220 mounted to bone surface 201 of bone 210having multiple fixation devices of the present invention installed tosecure the matrix 220. The number, anatomical location and orientationof fixation devices 10 necessary to provide sufficiently effectivefixation will vary with the size and type of implant or matrix, the typeof tissue, the age of the patient, the size of the patient's defect, thesize of the fixation devices, the material of construction of thefixation devices, the load on the tissue at the repair site, etc.

Those skilled in the art will appreciate that the size of the fixationdevices of the present invention will vary in accordance with a numberof variables including the specific design of the device, the materialsof construction, the specific application for the devices, the type ofsurgical procedure, etc. Similarly, the size of the matrices fixatedwith these devices will similarly vary. The Figures which are part ofthis specification are merely schematic and illustrative of the deviceand method of the present invention; the actual dimensions of thedevices and matrices may vary in practice.

The following example is illustrative of the principles and practice ofthe present invention although not limited thereto.

EXAMPLE

Six sheep were prepared for a surgical procedure using standard asepticsurgical techniques including the use of fully sterilized instrumentsand equipment, and conventional anesthesia procedures and protocols. Thesurgeon then created 7 mm diameter chondral (full thickness cartilage)defects on a weight-bearing area of the medial femoral condyle and inthe trochlear groove in the right stifle (knee) in each of the sixskeletally mature sheep. Defects were created using a specialized drillwith a depth-stop to prevent subchondral bone exposure or penetration.The base surfaces of all the defects were then microfractured with aspecialized micropick tool to provide access for cellular migration. Thesubjects were then separated into three groups of two subjects each:

-   -   Group 1: defect filled with a collagen matrix, fixed with the        graft fixation device of the present invention.    -   Group 2: defect filled with a collagen matrix, fixed with 9-0        absorbable Vicryl™ suture (interrupted stitch technique,        approximately 12 strands per matrix).    -   Group 3: unfilled defect (control group).

Both defects in a given stifle received the same treatment or served ascontrols.

For the two sheep in Group 1, after a defect had been created andmicrofractured, a punch tool 400 was used to create the two requisitebore holes in the subchondral bone to receive one graft fixation deviceof the present invention. Only one polydioxanone device (4 mm tip-to-tipdistance) was used to attach each matrix. To create the bore holes, thepunch tool was centered in the defect, oriented in the sagittal plane,and hit or “tapped” with a slap hammer repeatedly until it penetratedseveral millimeters into the subchondral bone. Next, a 7 mm diametercircular collagen matrix, saturated with saline, was placed in thedefect and then blotted dry to remove excess saline. When the insertertool 250 was loaded with the graft fixation device 10 of the presentinvention, the device and inserter tool were centered above the matrixand oriented in the sagittal plane. The surgeon then located thepreviously created bore holes by slowly advancing the distal tips of theinserter through the matrix. Once the surgeon located the holes with theinserter tips, a hammer was used to fully advance the inserter tool (andimplantation members 20 of the fixation device 10) through the matrixand into the subchondral bone. The inserter tool had a depth stop toprevent the implantation members 20 from being inserted too deeply,thereby assuring the proper placement of the implantation membersthrough the matrix. The insertion was completed when the connectingretention member between the two implantation members initially startedto compress the collagen matrix, thereby indicating secure fixation withthe underlying subchondral bone. After the two defects in a given stiflehad each been repaired with a matrix and fixation device, the stifle wasclosed and the sheep was allowed to recover. It was noted by the surgeonthat it took approximately one minute to attach a matrix with a fixationdevice of the present invention (Group 1), versus approximately 15minutes to attach a matrix with suture alone and the requisite suturemanipulation and knot tying (Group 2).

Two weeks after the surgeries were completed, the knee joints weresurgically opened for examination. Gross macroscopic assessment of thejoints demonstrated that all four matrices held by the graft fixationdevice of the present invention were fully intact. However, all fourmatrices held by sutures alone were only partially intact with, onaverage, approximately 30% of the sutures broken on any given matrix.

Another embodiment of the fixation device of the present inventionhaving multiple retention members is seen in FIG. 9. The device 300 isseen to have a pair of implantation members 310. The implantationmembers 310 are substantially cylindrical members having longitudinalaxis 311, distal ends 314 and proximal ends 312. Each implantationmember 310 is seen to have a longitudinal passage 320. The members 310are seen to have a distal frustoconical end 330, outer surface 350, andridges 355 extending outward from surface 350. The members 310 are seento be connected by a pair of retention members 340, having first andsecond ends 342 and 344 respectively.

Yet another embodiment of a fixation device of the present invention isillustrated in FIGS. 13-17. The graft fixation device 500 is seen tohave implantation members 520. The implantation members 520 are seen tobe elongated members, preferably having a substantially cylindricalshape. The members 520 may have other geometric shapes includingconical, pyramidal, polygonal, cubic, spherical, etc. The implantationmembers 520 are seen to have distal ends 522 and proximal ends 524. Eachimplantation member 520 is seen to have an outer surface 528 and alongitudinal axis 529. Each member 520 is also seen to have longitudinalpassage 535 extending therethrough. The implantation members 520 arealso seen to have optional frustoconical ends 530, and proximal end facesurfaces 532. Although it is preferred that endface surfaces 532 beflat, endface surfaces 532 may also be angled, concave, convex, etc.Each endface surface 532 is seen to have central circular opening 536 incommunication with passage 535. Preferably, central opening 536 willhave a circular cross-section, but it may have other geometriccross-sections as well including elliptical, polygonal, square,rectangular, combinations thereof and the like. Members 520 are alsoseen to have distal end face surfaces 537 having circular openings 538in communication with passages 535. Preferably, endface surfaces 537have a sharp edge configuration, but may also have various widths with arounded or flat configuration. As shown with the optional frustoconicalend 530, the annular end face surface 537 is of de minimis thicknessaround opening 538, however this thickness would typically increase inthe absence of a frustoconical end. However, although not preferred,even with a frustoconical, the end surface 537 could have various widthsas previously mentioned. Also seen to extend out from the surface 528 ofmember 520 are a series of optional projections 540 having tissueengagement edges 544. Without the projections 540, the surface 528 ofthe member 520 will be smooth, however, it will be appreciated thatsurface 528 could be rough, or could have a variety of conventionalprojections such as cones, hemispheres, rods, hooks, etc., and the likeand equivalents thereof.

The device 500 is seen to have graft retention member 550 connecting theimplantation members 520. Retention member 550 is seen to be a band-likemember preferably having an oval cross-section. The retention member 550is seen to have first end 552, second end 554 and central section 555.First end 552 is seen to extend up from proximal endface surface 532 ofthe first member 520 while end 554 is seen to extend up from theproximal endface surface 532 of the other member 520. A section 557 ofend 552 is seen to extend out from section 539 of surface 528, whilesection 558 of second end 554 is also seen to extend out from a section539 of surface 528. The ends 554 and 552 of retention member 550 may ifdesired extend from or be mounted to any section of outer surface 528.The connecting member 550 is seen to be preferably bent or shaped intothree segments including top segment 555 and leg segments 556. The topsegment 555 is seen to an arc shaped member, and the leg segments 56 areseen to be preferably perpendicular to surfaces 532. Although it ispreferred that connecting member 550 have an inverted “U” configuration,the connecting member 50 may have other geometric configurationsincluding semicircular, arced, curved, triangular, polygonal, V-shaped,and the like and combinations thereof. The ends 552 and 554 ofconnecting member 550 may be permanently affixed to the implantationmembers 520, or may be removably attached thereto in a variety ofconventional manners, for example, a ball and socket joint, a plugjoint, etc. Member 550 may be rigid or flexible. Member 550 will have asufficient surface area to effectively retain a tissue-engineered matrixin place on a bone or other body surface. Preferably, connecting member550 will have an oval cross-section, but may have other geometriccross-sections as well including circular, elliptical, polygonal,square, rectangular, combinations thereof and the like. Member 550 maybe rigid or flexible, and may have a single filamentary structure orhave multiple interconnected filaments or members.

An embodiment of graft fixation device 500 having lateral wing members580 is seen in FIGS. 35 and 36. Referring to FIG. 35, the device 500 isseen to have wing members 580 extending laterally from the centralsection 555 of the connecting member (or graft retention member) 550.The wing members 580 are preferably elongated members having a distalend 584 and a proximal end 582. Extending from the distal end 584 is arounded nose section 590. If desired nose section 590 may have othergeometric configurations including conical, pyramidal, and the like,etc. The wing members 580 are seen to have outer surface 586. As seen inFIG. 35, the wing members 580 are seen to have a circular cross-section,tapering from a maximum dimension at proximal end 582. There is seen tobe a transition section 592 between the proximal end 582 and the top 555of retention member 550. If desired, the diameter may be constant alongthe length of the wing member 580. The wing members 580 may have othercross-sectional configurations as well including oval, square,rectangular, triangular, polygonal, curved, combinations thereof and thelike. The length of the wing members 580 is sufficient to provideeffective retention of an implant graft. If desired, although notpreferred, the wing members 580 may short or of medium length, ratherthan elongated. Similarly, the width or diameter of the wing memberswill vary to provide sufficiently effective graft retention. Although itis preferred to have two opposed wing members 580 extending laterallyfrom the retention member 550, a single wing member 580 may be used, ora plurality of wing members 580 may be used with device 500. Theretention devices 500 having wing members 580 are illustrated implantedin bone and securing a graft matrix implant in FIG. 36. The method ofimplanting a device having wing members 580 is substantially similar,and having the same steps, to implanting a device 500 without wingmembers 580 as described and illustrated previously herein. As seen inFIG. 36, at least a portion of surface 586 engages the top of the matrix220 on bone 210.

Another aspect of the present invention is a distal insertion member(device) useful with the fixation devices of the present invention. Asseen in FIG. 18, the insertion device 600 is seen to be a substantiallycylindrical member having proximal end 610 and distal end 620. Proximalend 610 is seen to have a flat end surface 612. Frustoconical endsection 630 is seen to extend distally from distal end 620, althoughdevice 600 may have other configurations as well. If desired, distal end620 can have any tapered or curved configuration, but it is preferredthat it have a frustoconical end section extending therefrom. Thefrustoconical end section 630 is seen to have outer surface 632 anddistal tip 640. The member 600 is also seen to have exterior surface650. Extending through member 600 is the longitudinal passage 660 havingfirst circular opening 665 in communication therewith, and secondcircular opening 667 in tip 640 in communication therewith. Theinsertion members 600 are used in combination with the fixation membersof the present invention to engage the fixation member in bonesimultaneously with tapping the bore holes into bone, therebyeliminating the need for a separate step to form the bore holes prior toinserting the fixation member.

Referring to FIGS. 19-21, the previously mentioned combination of aninsertion member 600 and a fixation member 500 is illustrated.Initially, a fixation member 500 is mounted to prongs 700 extending fromthe distal end 415 of the shaft 405 of instrument 400. Each prong 700 isseen to have first cylindrical section 710 extending from the distal end415 of the shaft 405. Each cylindrical section 710 is seen to haveproximal end 711 and distal end 712, and receiving grooves 715.Extending from the distal end 712 of each first section 710 is thecentral pin section 720. Central pin section 720 is seen to haveproximal end 722 and distal end 724. Extending distally from distal end724 of central pin section 720 is the distal pin member 730. Distal pinmember 730 is seen to have proximal end 732 and distal pointed end 734.

If desired, the insertion member 600 may be molded into or affixed tothe distal end of an implantation member 520, thereby forming a unitarystructure as seen in FIG. 31 and FIG. 32. In addition, the insertionmember 600 may be mounted to the distal end of an implantation member520 in a conventional manner by gluing, cementing, mechanical fastening,friction fit and the like and equivalents thereof.

The combination of a unitary implantation device 500 having wing members580 as previously described and an insertion member 600 is illustratedin FIGS. 33 and 34. This combination with wing members 580 securing amatrix 220 to bone 210 is seen in FIG. 34. If desired, although notshown, the insertion members 600 may be separate from the insertiondevice 500 having wing members 580. The method of inserting thiscombination having wing members 580 is substantially identical to thatdescribed and illustrated herein.

The combination of the insertion members 600 and fixation members, suchas fixation member 500 of the present invention, are used to affix amatrix to bone in the following manner. Initially, the implantationmembers 520 of a fixation device 500 are placed upon prongs 700 of aninstrument 400 such that the leg members 556 are at least partiallyengaged in grooves 715 in first section 710 (see FIG. 21), and,intermediate sections 720 of pin members 700 are engaged in passages 535of implantation members 520, while pin members 730 extend out from thedistal ends of the implantation members 520. Then, insertion members 600are placed over the pin members 730, such that the pin members 730 areengaged in passages 660, and such that the pointed piercing ends 734extend beyond the distal ends 640 of the insertion member 660. Then, thetool 400 and the assembly consisting of fixation device 500 andinsertion member 600 is placed over a tissue matrix 220 placed upon abone 210. The piercing points are then pressed through matrix 220 tocontact the surface 211 of bone 210. A slap-hammer section of instrument400 is engaged to drive the piercing points 734, insertion members 600and implantation members 520 into the bone 210 as bore holes 200 areformed in the bone. The instrument 400 is then withdrawn proximately,thereby removing the intermediate sections 720 of prongs 700 from theimplantation members 520 and the pin members 730 from the insertionmembers 600, leaving the insertion members 600 and the implantationmembers 520 securely in the bone (as seen in FIG. 20). This completesthe affixation of the matrix 220 to the bone 210 using a single step,wherein the bore holes in the bone are formed simultaneously asinsertion members 600 and fixation device 500 are emplaced in the bone.

It is particularly preferred to use conventional remote visualizationsurgical procedures when inserting the fixation devices of the presentinvention. For example, inserting a scope through a trocar cannula intothe joint or body cavity, while insufflating the joint or body cavity.

The insertion members 600 will typically be made from a strong, hard,bioabsorbable material such that they can be driven into bone withoutfracturing or breaking. Examples of the types of materials which can beused to make the insertion member 600 include polylactic acid,polyglycolic acid, tricalcium phosphate, calcium phosphate, tetracalciumphosphate and hydroxyapatite, and any copolymers, mixtures or blendsthereof. Although not preferred, it is possible to make the insertionmembers from a conventional biocompatible material which is notbioabsorbable or biodegradable, such as titanium, stainless steel,ceramics, Nitinol and the like and equivalents thereof. The insertionmember 600 assists in forming the bore holes 200 while protecting theimplantation members 520.

FIGS. 22-23 illustrate a disposable distal end assembly 800 for aninstrument 400 of the present invention. When using the disposableassembly 800, it is preferable that the distal end 415 of the shaft 405of instrument 400 have screw threads 418, although other conventionaldetachable mounts may be used, for example a bayonet-type mount, lockinglevers and tabs, male and female mating sections, etc. As seen in FIGS.22-25, the assembly 800 consists of housing 810 having proximal end 811and distal end 817. Housing 810 is seen to have hollow cavity 815therein. Cavity 815 is seen to be in communication with proximal endopening 812 and distal end openings 820. Member 810 is seen to haveouter surface 822. Outer surface 822 is preferably knurled to facilitatethe grasping and turning of the housing 810. Housing 810 is further seento have distal end surface 825. The outer surface 822 is seen to have atapered section 823 that tapers toward end face 825. Contained withincavity 815, on inner surface 818 are the screw threads 819. Assembly 800is also seen to have driving pin members 830. Each driving pin member830 is seen to have proximal disk member 832 mounted to proximal end831, shaft section 834 and distal pointed end 838. Surrounding eachopening 820 on the interior of the member 810 are the annular recesses840. The assembly 800 is mounted to the distal end 415 of the instrument400 in the following manner. The pins 830 are inserted into cavity 815and through openings 820 such that the shafts 834 and distal piercingpoints 838 extend through end face 825, and the disk members 832 arecontained within the annular recesses 840. Then, the housing 810 ismounted upon the threads of distal end 415 such that threads 418 engagemating threads 819, and screwed further such that the proximal endsurfaces 833 of the disk members 832 are in contact with the distal endface 416 of distal end 415. After use in a surgical procedure, theassembly 800 is removed and discarded. A new sterile assembly 800 isutilized with a cleaned and sterilized instrument 400 for each newprocedure.

Referring now to FIGS. 26-30, a disposable end assembly 900 for mountingto an insertion instrument 250 is illustrated. The insertion member 250is seen to have distal end 264, having endface 265 and screw threads266. The assembly 900 is seen to have housing 950. Housing 950 hasproximal end 952 and distal end 956 and exterior surface 954. Extendingfrom distal end 956 is the plate member 960. Plate member 960 is seen tohave distal surface 962. The exterior surface 954 is seen to haveoptional knurling and distal tapered section 957 tapering into platemember 960. Housing 950 is seen to have internal cavity 955. Housing 950is also seen to have proximal opening 951 in communication with cavity955 and distal openings 970 also in communication therewith. Housing 950is seen to have internal screw threads 959 extending from internalsurface 958. Also contained within the interior of housing 950 in thedistal end 956 is the recessed groove 980. Assembly 900 is mounted tothe distal end 264 of instrument 250 in the following manner. Pins 910are inserted through cavity 950 and openings 970 such that proximalmembers 922 are engaged in groove 980. Sections 920 and 930 of pins 910extend through openings 970. Sections 920 are seen to have grooves 925.Then, the housing 950 is screwed on to distal end 264 such that thethreads 266 engage the mating internal threads 959 of housing 950. Thehousing is tightened until the distal end surface 265 of the distal end264 engages the top surfaces 923 of members 922. After a surgicalprocedure, the assembly 900 is removed from instrument 250 anddiscarded. A new sterile assembly 900 is utilized with a cleaned andsterilized instrument 250 for each new procedure.

Another alternate embodiment of the graft fixation members of thepresent invention is illustrated in FIGS. 37-41. An embodiment of agraft fixation device 1000 having optional lateral wing members 1080 isseen. Referring to FIGS. 37 and 38, the device 1000 is seen to have wingmembers 1080 extending laterally from the central section 1055 of theconnecting member (or graft retention member) 1050. Retention member1050 is seen to be a band-like member preferably having an ovalcross-section (See FIGS. 40 and 41). The retention member 1050 is seento have first end section 1052, second end section 1054 and centralsection 1055. First end 1052 is seen to extend up from proximal endfacesurface 1112 of the first member 1100 while end 1054 is seen to extendup from the proximal endface surface 1112 of the other member 1100. Asection 1057 of end 1052 is seen to extend out from a section of outersurface 1114, while a section 1058 of second end 1054 is also seen toextend out from a section of outer surface 1114. The ends 1054 and 1052of retention member 1050 may if desired extend from or be mounted to anysection of outer surface 1114, or extend solely from proximal endsurfaces 1112. The connecting or retention member 1050 is seen to bepreferably bent or shaped into three segments including top segment orcentral section 1055 and leg segments or end sections 1056. Although itis preferred that connecting member 1050 have an inverted “U”configuration, the connecting member 1050 may have other geometricconfigurations including semicircular, arced, curved, triangular,polygonal, V-shaped, and the like and combinations thereof. The ends1052 and 1054 of connecting member 1050 may be permanently affixed tothe implantation members 1110, or may be removably attached thereto in avariety of conventional manners, for example, a ball and socket joint, aplug joint, etc. Member 1050 may be rigid or flexible. Member 1050 willhave a sufficient surface area to effectively retain a tissue-engineeredmatrix in place on a bone or other body surface. Preferably, connectingmember 1050 will have an oval cross-section, but may have othergeometric cross-sections as well including circular, elliptical,polygonal, square, rectangular, combinations thereof and the like.Member 1050 may be rigid or flexible, segmented, or may have a singlefilamentary structure or have multiple interconnected filaments ormembers.

The optional and preferred wing members 1080 are preferably elongatedmembers having a distal end 1084 and a proximal end 1082 Extending fromthe distal end 1084 is a rounded nose section 1090. If desired nosesection 1090 may have other geometric configurations including conical,pyramidal, and the like, etc. The wing members 1080 are seen to haveouter surface 1086. The wing members 1080 preferably have an ellipticalor circular cross-section, tapering from a maximum dimension at proximalend 1082. There is seen to be a transition section 1092 between theproximal end 1082 and the central section 1055 of retention member 1050.If desired, the diameter may be constant along the length of the wingmember 1080. The wing members 1080 may have other cross-sectionalconfigurations as well including oval, square, rectangular, triangular,polygonal, curved, combinations thereof and the like. The length of thewing members 1080 is sufficient to provide effective retention of animplant graft and maintain contact of the implant against a bone, forexample, a bone surface. If desired, although not preferred, the wingmembers 1080 may be of short or medium length, rather than elongated.Similarly, the width or diameter of the wing members will vary toprovide sufficiently effective graft or matrix retention and contact ofthe graft or matrix with the bone. Although it is preferred to have twoopposed wing members 1080 extending laterally from the retention member1050, a single wing member 1080 may be used, or a plurality of wingmembers 1080 may be used with device 1000.

The members 1100 are seen to have a top section and a bottom section.The top section consists of implantation member 1110 and a lower sectionconsists of penetrating insertion member 1150. The upper implantationmember 1110 is seen to be a substantially cylindrical member having aproximal end 1120 and a distal end 1130. Preferably the distal end has afrustoconical configuration. Extending through implantation membersection 1110 is the passage 1140. Passage 1140 is seen to be anelongated passage. An opening 1141 in proximal endface 1112 ofimplantation member 1110 is seen to be in communication with the passage1140. Distal opening 1145 is also seen to communicate with passage 1140.The implantation member section 1110 is seen to have outer side surface1114. Extending radially outward from outer surface 1114 is at least oneengagement member 1117 having edge 1118 forming a ridge.

The penetrating insertion member sections 1150 are seen to have proximalends 1160 and distal ends 1170. The distal end 1170 preferably has adistal penetrating tip 1175. Tip 1175 may be blunt or sharp. Eachpenetrating insertion section 1150 is seen to be a substantiallyconically shaped member having proximal end face 1165 having opening1191 therein. The insertion member sections 1150 are further seen tohave longitudinal passages 1190 having blind end walls 1195. Passage1190 is seen to be in communication with opening 1191 which in turn isin communication with opening 1145, and accordingly passages 1140 and1190 are in communication with each other. If desired, although notpreferred, passage 1190 can continue through the length of insertionmember 1150, with a constant or smaller or tapering diameter, and blindend wall 1195 could be replaced with a flange having an opening or amember protruding radially inward into passage 1190 to engage the distalend of a mounting pin of an insertion instrument.

The graft fixation devices 1000 are made in a conventional mannerpreferably from bioabsorbable materials as previously mentioned forother embodiments of the fasteners disclosed herein. It is particularlypreferred to co-mold the implantation member section and the insertionmember section, although other conventional means of affixing theimplantation member and the insertion may be used including mechanicalfastening, welding, adhesives, glues, and the like and combinationsthereof. The penetrating insertion member sections 1150 will typicallybe made from a strong, hard, bioabsorbable material such that they canbe driven into bone without fracturing or breaking. Examples of thetypes of materials which can be used to make the penetrating insertionmembers 1150 include polylactic acid, polyglycolic acid, tricalciumphosphate, calcium phosphate, tetracalcium phosphate and hydroxyapatite,and any copolymers, mixtures or blends thereof and equivalents thereof.Although not preferred, it is possible to make the insertion membersfrom a conventional biocompatible material which is not bioabsorbable orbiodegradable, such as titanium, stainless steel, ceramics, Nitinolnickel-titanium alloy, polysulfone, acetal and the like and equivalentsand combinations thereof. The penetrating insertion members 1150 can bemade from conventional processes, including machining, molding,combinations and equivalents thereof and the like. The penetratinginsertion members 1150 assist in forming the implantation or bore holes200 while protecting the implantation member sections 1110. Theimplantation member sections 1110 can be made from conventionalbio-compatible materials, including absorbable and non-absorbablematerials, as well as biodegradable materials. The non-absorbablematerials which can be utilized include conventional biocompatiblematerials such as stainless steel, polyethylene, Teflon, Nitinol,non-absorbable polymers, other bio-compatible metals, ceramics,combinations thereof and the like. The absorbable materials which can beused to manufacture the implantation members 1110 will typically includethose conventional bioabsorbable or bioresorbable materials known inthis art which can be effectively molded or machined. The bio-absorbableand bio-resorbable materials include polylactic acid, polydioxanone,polycaprolactone, polyglycolic acid, polygalactic acid, other knownbiocompatible bioabsorbable and bioresorbable polymers, ceramics,composites, combinations thereof and the like and equivalents thereof.If desired the implantation members 1110 and the insertion members 1150can be made from the same material.

The graft fixation devices 1000 having wing members 1080 are illustratedimplanted in bone 205 and securing a graft matrix implant 220 to thesurface 210 of the bone 205 in FIG. 39.

An instrument 1400 and an instrument assembly 1600 useful for implantinggraft fixation devices 1000 is illustrated in FIGS. 42-45. Theinstrument 1400 is seen to have shaft 1410 having proximal end 1415 anddistal end 1418. Extending proximally from proximal end surface 1416 ofproximal end 1415 is threaded rod connector 1417. The shaft 1410 is seento have a tapered end section 1430 extending from distal end 1418.Extending laterally (radially) out from shaft 1410 toward proximal end1415 are the guide pins 1420. Extending out distally from tapered end1430 are the mounting pins or mounting members 1450 having proximal ends1452 and distal ends 1457 having distal flat end faces 1458. The sleevemember 1470 is seen to be a tubular member having distal end 1477 andproximal end 1472. The member 1470 has inner or longitudinal passage1480 in communication with distal opening 1485 and proximal opening1482. The member 1470 has outer surface outer surface 1475, and aproximal handle section surface 1476 extending therefrom. The sleevemember 1470 is seen to have a plurality of openings 1490 extendingtherethrough in the distal end 1477 in communication with inner passage1480. The openings 1490 act as windows so that the interior of sleevemember 1470 may be viewed adjacent thereto. The sleeve member 1470 isseen to have opposed longitudinal slots 1492 extending therethrough inthe proximal end 1472. The sleeve member 1470 is concentrically andslidably mounted over shaft 1410 such that the pins 1420 are containedwithin slots 1492, and mounting pins 1450 are contained within passage1480 adjacent to distal end 1477 of sleeve member 1470, or extending outfrom distal end 1477 of sleeve member 1470.

An assembled insertion instrument assembly 1600 is seen in FIG. 43,having the sleeve member 1470 in the maximum proximal position to exposethe mounting members 1450. The insertion instrument assembly 1600 isseen to have insertion instrument 1400 with an optional conventionalslap hammer assembly 1530 mounted to the proximal end 1415 of shaft1410. The slap hammer assembly 1530 is seen to have a tapered connectingsection 1540 having distal end 1541 and proximal end 1546. Distal end1541 is seen to have threaded cavity 1542 extending therein, andproximal end 1546 is seen to have threaded cavity 1547 extendingtherein. The slap hammer assembly 1530 is seen to have support rod 1550having proximal end flange 1555 and distal threaded end 1558. Theassembly has handle member 1560 slidably mounted on rod 1550. Handlemember 1560 is seen to have longitudinal passage 1568, proximal flangemember 1562 and distal flange member 1564. The threaded end 1558 ofsupport rod 1550 is engaged in threaded cavity 1547 of taperedconnecting section 1540. The threaded rod connector 1417 of shaft 1410is similarly engaged in threaded cavity 1542 of connecting section 1540.The insertion instrument 1400 may be used without slap hammer assemblyto insert graft fixation devices of the present invention. For example,the proximal end 1415 of shaft 1410 may be connected to otherconventional force transmitting devices, or the proximal end 1415 may behammered directly by the surgeon using a conventional orthopedic hammer.

A method of implanting a graft fixation device 1000, having optionalwing members 1080, using an insertion instrument assembly 1600 isdescribed as follows. It should be noted that although it is preferredto insert the graft fixation devices 1000 directly into bone using theinsertion instrument assembly 1600 without pre-drilling or otherwisepre-creating bore holes in bone, the device 1000 can also be utilized toaffix a matrix to bone where the bore holes are pre-drilled or otherwisepre-created.

In using the graft fixation device 1000 of the present invention havingoptional wing members 1080 with insertion instrument assembly 1600, anincision is made in a conventional manner to access the patient's bone(via a conventional arthroscopic or open procedure) where it is desiredto implant a matrix. After the matrix 220 is positioned on the surface210 of bone 205 as seen in FIG. 39, a device 1000 is mounted to themounting pins 1450 of insertion instrument 1400 of insertion assembly1600. Next the sleeve member 1470 is moved distally to cover theinsertion device 1000, thereby protecting the device 1000, and thesurgeon locates the device at the surgical site using insertioninstrument assembly 1600. Next, the surgeon slides the sleeve 1470proximally to uncover the insertion device 1000. Then, the distal end ofpenetrating insertion member 1150 is contacted with the top 221 of thematrix 220. The optional slap hammer assembly 1530 is manipulated todrive the penetrating insertion member 1150 and the implantation member1100 into the bone 205. This causes the central section 1055 ofretention member 1050 and the lateral wing member 1080 to engage thematrix 220 and substantially cause the bottom surface 222 of the matrix220 to engage the surface 210 of the bone 205. Multiple fixation devices1000 are inserted in the same manner into the matrix 220 in a spatialconfiguration sufficient to effectively affix or mount the matrix 220 tothe bone 205. During insertion with the insertion instrument assembly1600 having insertion instrument 1400 and slap hammer assembly 1530, thedistal flat end faces 1458 of pins 1450 contact end walls 1195 ofpassage 1190 causing a transfer of force from the mounting pins 1450 topenetrating insertion members 1150 thereby driving the device thepenetrating insertion members 1150 and the implantation members 1110into the bone 205.

The fixation devices of the present invention and the combination of thefixation devices with insertion members, and methods of using suchdevices and combinations, of the present invention have many advantages.The advantages include providing a fast and routine way to fixate amatrix of tissue engineered tissue or other tissue. The fixation devicesand combination, because they eliminate the need for suture knot tying,can be utilized in arthroscopic surgical procedures that require aminimum of surgical incisions and thus greatly reduce patient morbidity.In addition, the fixation devices and combination have been demonstratedto provide excellent matrix fixation without damaging the surroundingnormal cartilaginous tissue, unlike the conventional fixation ofchondral defect matrices with traditional suture that must be passedthrough (and thus damage) the surrounding tissue.

Although this invention has been shown and described with respect todetailed embodiments thereof, it will be understood by those skilled inthe art that various changes in form and detail may be made withoutdeparting from the spirit and scope of the claimed invention.

1. A method of mounting a matrix to a bone, the method comprising:providing a graft fixation device comprising: a first implantationmember, said implantation member having a longitudinal axis, a proximalend, a distal end, an outer surface, a longitudinal passagetherethrough, a proximal opening and a distal opening, wherein bothopenings are in communication with the passage; a second implantationmember, said implantation member having a longitudinal axis, a proximalend, a distal end, an outer surface, a longitudinal passagetherethrough, a proximal opening and a distal opening, wherein bothopenings are in communication with the passage; a retention memberconnecting the first and second implantation members, the retentionmember having a central section, a first end section extending from thefirst implantation member and a second end section extending from thesecond implantation member; and, an insertion member extending from thedistal end of each implantation member, wherein the insertion member hasa proximal end, a distal end, an outer surface, a proximal opening and alongitudinal passage in communication with the proximal opening, whereinsaid longitudinal passage has a distal blind end, and wherein thelongitudinal passage of each insertion member is in communication withthe longitudinal passage of the respective implantation members; and, atleast one wing member extending from the retention member; accessing abone; positioning a matrix member to the surface of the bone, saidmatrix member having a top surface and a bottom surface; mounting thegraft fixation device to an instrument having a shaft having a distalend, a proximal end, and distal mounting pins extending from the distalend of the shaft, wherein the pins are engaged in the longitudinalpassages of the implantation members and insertion members; and,manipulating the shaft such that the insertion members are caused topenetrate the matrix and the bone, thereby causing the implantationmembers to engage the bone, and the retention member to engage thematrix such that at least a section of matrix is maintainedsubstantially in contact with the bone.
 2. The method of claim 1 whereinthe implantation members have a series of ridges extending from theouter surfaces thereof.
 3. The method of claim 1, wherein the retentionmember comprises a semicircular configuration.
 4. The method of claim 1,wherein the implantation members comprise a substantially cylindricalconfiguration.
 5. The method of claim 1 wherein the insertion membercomprises a bioabsorbable material selected from the group consisting ofpolylactic acid, polyglycolic acid, tricalcium phosphate, calciumphosphate, tetracalcium phosphate and hydroxyapatite, and copolymers,mixtures and blends thereof.
 6. The method of claim 1 wherein theinsertion member comprises a biocompatible material selected from thegroup consisting of titanium, stainless steel, ceramic, and Nitinol. 7.The method of claim 1 wherein the fixation device comprises abioabsorbable polymer.
 8. The method of claim 1 wherein the fixationdevice comprises two opposed wing members extending from the retentionmember.
 9. The method of claim 1, wherein the implantation memberscomprise a cylindrical shape having a distally extending frustoconicalend.
 10. The method of claim 1, wherein the insertion members have aconical configuration with a distally extending tip portion.
 11. Themethod of claim 1, wherein the retention member comprises an ellipticalconfiguration.
 12. The method of claim 12, wherein the retention membercomprises an elliptical configuration.
 13. The method of claim 1 whereinthe implantation member comprises a bioabsorbable polymer selected fromthe group consisting of polylactic acid, polydioxanone,polycaprolactone, polygalactic acid, polyglycolic acid, and combinationsthereof.